keep board horizontal scroll across refresh: restore scrollLeft after #board-container rebuild; v1.0

Asset/js/keep-scroll.js

@@ -0,0 +1,55 @@
+/*
+ * OrganonTweaks -- keep the board's horizontal scroll position across refreshes.
+ *
+ * When you drop a card (and on Kanboard's periodic AJAX polling) the board is rebuilt with
+ * `$("#board-container").replaceWith(data)` (BoardDragAndDrop.refresh). The brand-new
+ * element starts at scrollLeft 0, so the board snaps back to the first column -- a jarring
+ * jump. This remembers the last scroll position and restores it the moment a replacement
+ * container appears, so the view stays put.
+ *
+ * We observe the STABLE parent (the container itself is replaced) and read the scroll from
+ * whichever #board-container is current, so it keeps working after every rebuild.
+ */
+(function () {
+    "use strict";
+
+    function init() {
+        var container = document.getElementById("board-container");
+        if (!container) {
+            return;
+        }
+
+        var parent = container.parentNode;
+        var lastScrollLeft = container.scrollLeft;
+        var lastContainer = container;
+
+        // Remember the position whenever the board is scrolled (capture: scroll does not
+        // bubble, and this survives the container being replaced).
+        document.addEventListener("scroll", function (e) {
+            var c = document.getElementById("board-container");
+            if (c && e.target === c) {
+                lastScrollLeft = c.scrollLeft;
+            }
+        }, true);
+
+        // When the board is rebuilt, #board-container becomes a new element at scrollLeft 0;
+        // restore the remembered position before the browser paints it.
+        if (window.MutationObserver) {
+            new MutationObserver(function () {
+                var c = document.getElementById("board-container");
+                if (c && c !== lastContainer) {
+                    lastContainer = c;
+                    if (c.scrollLeft !== lastScrollLeft) {
+                        c.scrollLeft = lastScrollLeft;
+                    }
+                }
+            }).observe(parent, { childList: true });
+        }
+    }
+
+    if (document.readyState === "loading") {
+        document.addEventListener("DOMContentLoaded", init);
+    } else {
+        init();
+    }
+})();

Controller/ConfigController.php

@@ -15,6 +15,7 @@ class ConfigController extends BaseController
             'title' => t('Settings').' > '.t('Organon Tweaks'),
             'values' => array(
                 'organon_tweaks_always_comment_icon' => (int) $this->configModel->get('organon_tweaks_always_comment_icon', 1),
+                'organon_tweaks_keep_scroll' => (int) $this->configModel->get('organon_tweaks_keep_scroll', 1),
             ),
             'errors' => array(),
         )));
@@ -25,8 +26,12 @@ class ConfigController extends BaseController
         $values = $this->request->getValues();
 
         $alwaysCommentIcon = isset($values['organon_tweaks_always_comment_icon']) ? 1 : 0;
+        $keepScroll = isset($values['organon_tweaks_keep_scroll']) ? 1 : 0;
 
-        if ($this->configModel->save(array('organon_tweaks_always_comment_icon' => $alwaysCommentIcon))) {
+        if ($this->configModel->save(array(
+            'organon_tweaks_always_comment_icon' => $alwaysCommentIcon,
+            'organon_tweaks_keep_scroll' => $keepScroll,
+        ))) {
             $this->flash->success(t('Settings saved successfully.'));
         } else {
             $this->flash->failure(t('Unable to save your settings.'));

Plugin.php

@@ -26,6 +26,14 @@ class Plugin extends Base
         if ((int) $this->configModel->get('organon_tweaks_always_comment_icon', 1) === 1) {
             $this->template->hook->attach('template:board:task:icons', 'organonTweaks:board/task_comment_icon');
         }
+
+        // Tweak: keep the board horizontal scroll position across refreshes (Kanboard
+        // rebuilds #board-container on card drop / polling, resetting scrollLeft to 0).
+        if ((int) $this->configModel->get('organon_tweaks_keep_scroll', 1) === 1) {
+            $this->hook->on('template:layout:js', array(
+                'template' => 'plugins/OrganonTweaks/Asset/js/keep-scroll.js',
+            ));
+        }
     }
 
     public function getHelpers()
@@ -52,7 +60,7 @@ class Plugin extends Base
 
     public function getPluginVersion()
     {
-        return '0.3.1';
+        return '1.0.0';
     }
 
     public function getPluginHomepage()

README.md

@@ -35,11 +35,24 @@ have comments keep showing the count as before.
   read-only viewers).
 - **On by default.** Toggle it under "Settings -> Organon Tweaks".
 
+### Keep the board scroll position across refreshes
+
+When you drop a card (or Kanboard auto-refreshes the board via polling), it rebuilds the
+board with `$("#board-container").replaceWith(...)`, and the new element starts scrolled to
+the far left -- so the view jumps back to the first column. This tweak remembers the
+horizontal scroll position and restores it as soon as the rebuilt board appears, so the
+board stays where you were.
+
+- Implemented in `Asset/js/keep-scroll.js`: it observes the stable parent (the container
+  itself is replaced), reads/writes `scrollLeft` on whichever `#board-container` is current.
+- **On by default.** Toggle it under "Settings -> Organon Tweaks".
+
 ## Settings
 
 Global (per Kanboard instance) and admin-only, under "Settings -> Organon Tweaks":
 
 - **Always show the comment icon on board cards** -- default on.
+- **Keep the board scroll position across refreshes** -- default on.
 
 ## Requirements
 

Template/config/show.php

@@ -12,6 +12,13 @@
         </p>
     </fieldset>
 
+    <fieldset>
+        <?= $this->form->checkbox('organon_tweaks_keep_scroll', t('Keep the board scroll position across refreshes'), 1, isset($values['organon_tweaks_keep_scroll']) && $values['organon_tweaks_keep_scroll'] == 1) ?>
+        <p class="form-help">
+            <?= t('When a card is dropped (or the board auto-refreshes), Kanboard rebuilds the board and jumps back to the first column. This restores the horizontal scroll position so the board stays where you were.') ?>
+        </p>
+    </fieldset>
+
     <div class="form-actions">
         <button type="submit" class="btn btn-blue"><?= t('Save') ?></button>
     </div>

VERSION

@@ -1 +1 @@
-OrganonTweaks v0.3.1
+OrganonTweaks v1.0